Crankshaft truing tool



.1. L. TINDALL ET AL 2,148,329 CRANKSHAFT TRUING TOOL Feb. 21, 1939.

Filed July 22, I936 J L. Tn d a 1 1 PKMPa trick INVENTORS Mia 4401417 IATTfiNEY.

Patented Feb. 21, 1939 PATENT OFFICE CRANKSHAFT TRUING TOOL Jerome L.Tindall and Willie M. Patrick, Amarillo, Tex.

Application July 22, 1936, Serial No. 92,040

10 Claims.

The invention provides a tool of novel and peculiar constructiondesigned for truing or re conditioning crank shafts, and particularlyfor truing crank pins of internal combustion engines and analogousbearing members to eliminate fiat places and tapered conditions and thusprovide a perfectly cylindrical surface to assure smooth running andeven wear. The tool may be used on said parts while they are still inthe engine or it may be used in combination with a lathe.

Heretofore tools have been proposed for turning or truing crank shaftsor crank pins, but these were constructed more in the shape of longwrenches which prevented their use on the crank shaft in the engine andtherefore necessitated the removal of the crank shaft in order tooperate on the crank pins thereof. Such tools as have been proposed ofsubstantially symmetrical form were not constructed capable of beingapplied to the crank shaft in place in the engine.

The object of this invention is to provide a tool of the characterspecified in which the operating elements may be held in a circular, orother symmetrical form, and which tool is so constructed that it may bereadily attached to or removed from the crank shaft of an internalcombustion engine without necessitating removal of the crank shaft fromthe engine or the removal of associated parts, particularly theconnecting rod and 0 piston, and the subsequent replacement thereof.

The invention provides a tool that is adjustable within certain limitsto fit shafts or other work of different sizes and to properly centerthe work therein and the essential elements of which tool are held inproportional and operative relationship to each other.

While the drawing illustrates a preferred embodiment of the invention,it is to be understood that in adapting the same to meet specific needsand requirements, the design may be varied and changes in the minordetails of construction may be resorted to within the scope of theinvention as claimed, without departing from the spirit thereof.

For a full understanding of the invention and the merits thereof,reference is to be had to the following description and the drawinghereto .attached, in which:

Figure l is a side view of an embodiment of the invention showing itapplied to the crank shaft of an engine, the cylinder block of which isshown in section and the cylinder containing a piston which isdisconnected from the crank shaft.

Figure 2 is an enlarged perspective view of the Figure 3 is a detailsectional view on the line 33 of Figure 2, looking in the direction ofthe arrows.

The tool is constructed with a body 4 which is symmetrical in outline,preferably circular, which body 4 is preferably constructed rigidly inone piece. The body 4 has a radially extending opening IS in one sidethereof constituting a throat,

which throat is provided with parallel sides extending inwardly from theperiphery of the body 4, at least to the center thereof and having anarcuate inner end. The sides of the throat are spaced apart sufficientlyfar to enable the tool to be slipped over a crank pin or other work,designated generally by the numeral H in Fig. 1, to which it is adapted,so the work may be centered with respect to the body 4 for properturning of the body thereon during operation of the tool to provide acircular outline therefor in truing the work to the proper shape. Radialopenings l6 are spaced at intervals around the periphery of the body 4to receive a rod 2| which may be inserted therein for rotating the toolabout the crank pin H.

A centering rest 5is mounted in the body 4 at one side of the throat l5and on the opposite side thereof is a holding rest 1, arrangedsubstantially in alignment with the centering rest 5. Each of the rests5 and 1 is formed of substantially U-shape, as shown in Fig. 3, havingthe sides thereof slidably mounted in radially recessed grooves 25 inopposite sides of the body 4, while the rest is locked in place by oneor more locking screws 21], extending through slots [9 in the body 4 andengaging the opposite sides of the rest to. draw the same inwardly intobinding relation with the sides of the body 4 to hold the rest in thedesired adjusted position, as shown at the bottom of Fig. 3. Adjustingscrews I 8 and I0 extend radially in the body 4 and hear at their innerends against the rests 5 and 1, respectively, to adjust the restsradially with respect to the body 4, to accommodate work of differentsizes and to hold the work or crank pin in the proper position andproperly centered in the body 4. A scale I8 is provided on the body 4adjacent an edge of the rest 5 to cooperate with an indication on therest 5 for indicating the degree of adjustment of the rest, making itpossible to locate the centering rest in the desired position withrespect to the body 4, according to the character of work on which thetool is to be operated.

Mounted on the same side of the throat H: as the holding rest 1 is ablade holder 6, which is likewise of U-shape with the sides thereofslidably mounted in radially recessed grooves 25a, in the sides of thebody 4, being adjustable by a screw 9, mounted similar to the screws 8and I0, and the blade holder 6 is locked in place by means of a lockingscrew 20a, extending through a slot [9a in the body 4. The inner end ofthe blade holder 6 has a substantially wedge shaped groove thereinreceiving a cutting blade or working tool II, which is locked in placeby a block I2 secured by set screws to the inner end of the blade holder6.

The inner end of the centering rest 5 is constructed with sides or workengaging faces I3 and Na, arranged in substantially V-shape adjacent theinner end of the throat IE: to receive and properly center the work orcrank pin with respect to the body 4. The inner end of the holding rest1 has a face l4 between its oppositely inclined edges to engage the workon the opposite side thereof from the V-shaped faces 43 and Ma andcooperating therewith to hold the tool in proper rotatable relation withrespect to the work. The faces I3, Ba and M are hardened to resist wearby contact with the work.

The parts are so arranged that the working tool or blade ll lies in aplane extending radially through the center of the crank pin I1, andperpendicular to the face I3a, approximately midway of the length ofsaid face, which re lation enables the tool to turn the crank pin,bearing or other work to a true cylindrical form as desired. Theadjustment of the centering rest, holding rest, and blade holderradially with respect to the body 4, properly centers the tool on thework to obtain this cylindrical form of the work. The blade or workingtool H may be adjusted by screws 22 which extend substantiallylengthwise of the blade holder 6 at each side thereof, to bring itscutting edge into parallel relation ship with the faces I3 and I3a ofthe V-shaped centering rest.

It will be evident that the holding rest I should be retracted in thethroat l5 to permit the tool to be applied to the crank pin or otherwork. The adjustment of the centering rest 5 having been made forapplication of the tool to the crank pin, according to the size of thecrank pin on which the tool is to be used, the tool is slipped thereoveruntil the V-shaped centering rest fits properly on the crank pin, afterwhich the holding rest is adjusted by the screw I-D into relativelyclose contact with the opposite side of the crank pin to hold the toolfirmly but rotatably thereon. If proper adjustments have previously beenmade, the edge of the cutting tool II will be in proper operatingrelation to the periphery of the crank pin for truing the same uponrotation of the tool thereon, shaping the crank pin to a truecylindrical form. After the tool is properly fitted to the crank pin 'orother work, it is rotated intermittently by the rod 2|, being engaged inthe respective openings IS in the periphery of the tool, the rod beingshifted from one opening to another between stages of rotation, and thisoperation continued until the crank pin is shaped and trued as desired,after which the tool may be removed by withdrawal of the holding rest I.

It will be evident that the use and operation of this tool does notrequire the removal of the crank shaft from the engine, but it is onlynecessary to disconnect the connecting rod and move the piston into theupper portion of the cylinder in the cylinder block 23, as shown in Fig.1, thus eifecting a substantial saving of time and labor in performingthis operation.

It will be understood that the tool is of such construction that it maybe fitted to a crankshaft or other part to be trued withoutnecessitating the removal of such part from the engine in which it ismounted, or it may be used in combination with a lathe in this form or avariation thereof. The rests and cutter are each independently adjustedby the coacting adjusting screws in the manner stated. It is to befurther noted that cutter ll immediately follows rest I, this allowsadjustment of blade within close limits and allows uniform cutting without digging in or chattering. Due to the cutter H being closely spacedto the rear of rest 1, springiness is eliminated and a uniform cuttingis obtained. Again it is to be noted that by adjustment of rest 5 andcutter blade II, the surface l3a and the cutter blade ll have theirpoints of contact on the shaft diametrically opposite each other, thusdetermining the diameter of the shaft to be trued. The rest 1 holds thework firmly yet rotatably within the V of the centering rest 5, thusallowing a free and independent adjustment of cutter H.

Having thus described the invention, what we claim is:

1. A tool of the character described comprising a unitary rigidsymmetrical body of approximately uniform radius throughout, said bodyhaving an open work-receiving throat in a side thereof and extendingapproximately to the center of said body, a working tool in a side ofsaid throat, and means adjacent said working tool for holding the work,said body having means spaced at intervals around the periphery thereoffor turning the body.

2. A tool of the character described comprising a unitary rigidsymmetrical body of approximately uniform radius throughout, said bodyhaving a work-receiving throat in a side thereof and extendingapproximately to the center of said body, a working tool, means forholding the work adjacent said working tool, including a V-shapedcentering rest mounted at a side of the throat, and a holding restslidable radially of the body into the throat between the outer endthereof and the work.

3. A tool of the character described comprising a unitary rigidsymmetrical body of approximately uniform radius throughout, said bodyhaving an open work-receiving throat in a side thereof and extendingapproximately to the center of said body, a working tool, means forholding the work adjacent said working tool, including a V-shapedcentering rest mounted at a side of the throat, and a holding restslidable radially of the body into the throat between the outer endthereof and the work, the working tool being arranged in a plane passingapproximately through the center of the work in the holding means andintersecting one of the faces of the V-shaped centering rest.

4. A tool of the character described comprising a unitary rigidsymmetrical body of approximately uniform radius throughout, said bodyhaving an open work-receiving throat in a side thereof and extendingapproximately to the center of said body, a working tool, means forholding the work adjacent said working tool, including a V-shapedcentering rest mounted at a side of the throat, and a holding restslidable radially of the body into the throat between the outer endthereof and the work, the working tool Cir being arranged in a planepassing approximately through the center of the work in the holdingmeans and intersecting one of the faces of the V-shaped centering restapproximately perpendicular thereto.

5. A- tool of the character described comprising a body having a rigidV-shaped centering rest, means for adjusting said rest bodily relativeto the body, a holding rest carried by the body and cooperating with thecentering rest to hold work therein, and a Working tool carried by thebody, the plane of said working too-1 passing approximately through thecenter of the work in the rests and intersecting one of the faces of theV-shaped centering rest approximately perpen dicular thereto.

6. A tool of the character described comprising a body having a rigidV-shaped centering rest, means for adjusting said rest bodily relativeto the body, a holding rest carried by the body and cooperating with thecentering rest to hold work therein, a Working tool carried by the body,the plane of said working tool passing approm'mate- 1y through thecenter of the work in the rests and intersecting one of the faces of theV-shaped centering rest approximately perpendicular thereto, and meansfor adjusting said working tool and holding rest independently relativeto the centering rest.

'7. A tool of the character described comprising a unitary rigidsymmetrical body of approximately circular outline and having apermanently open work-receiving throat in a side thereof and extendingto the center of said body, means for holding work approximately at thecenter of said body, and a working tool mounted in said body in a sideof said throat adjacent the center thereof, said body having orificesspaced at intervals around the periphery thereof to receive operatingmeans therefor.

8. In a tool of the character specified, a symmetrical body having athroat with an open outer end, a radially adjustable V-shaped centeringrest mounted at a side of the throat, a radially adjustable holding restmounted in a side of the throat approximately opposite said V-shapedcentering rest, a radially adjustable cutting tool mounted approximatelyperpendicular to one of the faces of the V-shaped centering rest, andmeans for rotating the tool.

9. A tool of the character described comprising a unitary rigidsymmetrical body of approximately uniform radius throughout, said bodyhaving a work-receiving throat in a side thereof and extendingapproximately to the center of said body, a working tool in a side ofsaid throat, means for holding the work approximately at the center ofthe body, work holding means between said working tool and the outer endof the throat, said work holding means being slidable approximatelyradially of the body into the throat between the outer end thereof andthe work.

10. A tool of the character described comprising a unitary rigidsymmetrical body of approximately uniform radius throughout, said bodyhaving a work receiving throat in a side thereof and extendingapproximately to the center of said body, a working tool in a side ofsaid throat, means for holding the work approximately at the center ofthe body and adjacent said working tool, adjustable work holding meansslidable radially of the body in the throat between the outer endsthereof immediately forward and adjacent said working tool, said workholding tool being approximately diametrically opposite thefirst-mentioned work holding means, and said working tool beingapproximately diametrically opposite one of the contact faces of saidadjustable centering means.

JEROME L. TINDALL. WILLIE M. PATRICK.

